#include <bits/stdc++.h>
using namespace std;

#define int int64_t
#define endl "\n"

using PII = pair<int, int>;
using TII = tuple<int, int, int>;
template<class T> using V = vector<T>;
using i64 = long long;
using i128 = __int128;
using u64 = unsigned long long;

#define FOR(i, a, b) for (int i = (int)(a); i <= (int)(b); i++)
#define FOR2(i, a, b, c) for (int i = (int)(a); i <= (int)(b); i += c)
#define FORD(i, b, a) for (int i = (int)(a); i >= (int)(b); i--)
#define FORD2(i, b, a, c) for (int i = (int)(a); i >= (int)(b); i -= c)
#define ALL(a) a.begin(), a.end()
#define RALL(a) a.rbegin(), a.rend()
#define lowbit(x) ((x) & (-x))
#define RE return;
#define Yes cout << "Yes" << endl;
#define YES cout << "YES" << endl;
#define No cout << "No" << endl;
#define NO cout << "NO" << endl;
#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define sz(x) (int)(x).size()

void solve() {
    int n;
    cin >> n;
    string s;
    cin >> s;
    s = ' ' + s;
    V<int> num(n + 1, 0);
    iota(ALL(num), 0ll);
    V<V<int>> g(n + 1);

    FOR(i, 1, n) {
        FOR(j, 1, n - 1) {
            if (s[j] > s[j + 1]) {
                swap(s[j], s[j + 1]);
                swap(num[j], num[j + 1]);
                g[num[j]].eb(num[j + 1]);
                g[num[j + 1]].eb(num[j]);
            }
        }
    }

    V<int> c(n + 1, 0), vis(n + 1, 0);

    FOR(i, 1, n) {
        if (c[i] == 0) {
            function<int(int, int)> dfs = [&](int u, int cl) {
                c[u] = cl;
                for (auto j : g[u]) {
                    if (c[j] == c[u]) {
                        return 0;
                    } else if (c[j] == 0 && !dfs(j, -cl)) {
                        return 0;
                    }
                }
                return 1;
            };
            if (!dfs(i, 1)) {
                NO;
                RE;
            }
        }
    }
    YES;
    FOR(i, 1, n) {
        if (c[i] == 1) {
            cout << 0;
        } else {
            cout << 1;
        }
    }
}

signed main() {
    int Task = 1;

    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    while (Task--) {
        solve();
    }

    return 0;
}